The centre part of any business web template has to be kept for showing off products or services. In the centre if there is a place the products or service with little description the users can easily understand what type of business you are running or what they can get from your site. So it is necessary that the layouts give you scope to utilize the space for attracting your visitors cum customers.
Group Sites or Social Network Sites. There are usually dedicated sites for different groups depending on what they are doing. Social Networks are much broader, but groups within them like scrapmoms, scrapsisters, and so many more usually share their ideas and projects. It is up to you whether you will join any group if you want to get more details and interact with the people within the group, but you will get templates in there.